This invention relates to stencilling apparatus, and more particularly to screen stencilling, usually for printing, employing a direct, regulated flow through action from ahead of the squeegee to behind the flow coater, by passage over the squeegee into a control reservoir between the squeegee and the flow coater, and from the reservoir onto the stencil screen.
Screen stencilling is widely used for selectively depositing coating materials such as inks, adhesives, and other functional and/or decorative deposits through a screen stencil onto stock such as paper, polymers, cloth, wood, laminates, and the like for making posters, decalcomania coatings, graphic designs, and the like. A typical apparatus for screen stencilling is set forth in U.S. Pat. No. 2,606,492. Usually, the process involves the spreading of a layer of the fluid on a fine mesh screen, followed by forcing a portion of the fluid layer through the pattern areas of the screen with a squeegee, onto the stock. The excess ink is forced to one end of the screen by this squeegee. The excess ink is subsequently spread back onto the screen by a flow coater for the next stencilling stroke. A common tendency of the stencilling fluid is to thicken or even dry because of solvent or carrier liquid evaporation while the excess stencilling fluid is repeatedly wiped off the stencil screen ahead of the squeegee and spread again onto the stencil screen on the return stroke.